This is a digital data set including historical hydrographic sounding data collected by the US Army Corps of Engineers, Seattle District, within the Columbia River littoral cell (CRLC). The original data set has been reprojected to Washington Stateplane, FIPS 4602, meters. Attributes inlcude easting, northing, depth-navd(m), depth-mllw(m), cartographic code, survey name, and survey year.

Purpose:

This data set is intended for use as an historical bathymetric data set for scientific research. It is not intended for navigational use. The data were originally used for bathymetric change analysis as part of the Southwest Washington Coastal Erosion Study (SWCES), a cooperative study by the US Geological Survey and the Washington State Department of Ecology.

Supplemental_Information:

The SWCES was initiated to examine coastal geology, processes, and natural hazards within the Columbia River littoral cell. The study is jointly directed by the U.S. Geological Survey Coastal and Marine Geology Program and the Washington State Department of Ecology Shorelands and Environmental Assistance Program, with active participation of local communities in Pacific and Grays Harbor counties. Related USGS work in the Southwest Washington Coastal Erosion Study can be found online at: <http://www.ecy.wa.gov/programs/sea/swce/>

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 1927

Ending_Date: 1927

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -124.214410

East_Bounding_Coordinate: -124.056428

North_Bounding_Coordinate: 46.961085

South_Bounding_Coordinate: 46.887810

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: Hydrographic data

Theme_Keyword: Bathymetry

Theme_Keyword: Columbia River littoral cell

Theme_Keyword: Southwest Washington Coastal Erosion Study

Theme_Keyword: Bathymetric change

Place:

Place_Keyword_Thesaurus: none

Place_Keyword: Southwest Washington

Place_Keyword: Northern Oregon

Place_Keyword: Pacific Ocean

Place_Keyword: Pacific Northwest

Place_Keyword: Grays Harbor

Place_Keyword: Willapa Bay

Place_Keyword: Columbia River

Place_Keyword: USA

Access_Constraints: None

Use_Constraints:

Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

This information is not intended for navigational purposes.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Please recognize the U.S. Geological Survey (USGS) and the Southwest Washington Coastal Erosion Study (SWWCES) as the source of this information.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Ann E. Gibbs

Contact_Organization: USGS

Contact_Position: Geologist

Contact_Address:

Address_Type: mailing address

Address: 345 Middlefield Road MS999

City: Menlo Park

State_or_Province: CA

Postal_Code: 94025

Country: USA

Contact_Voice_Telephone: 650-329-5060

Contact_Electronic_Mail_Address: agibbs@usgs.gov

Data_Set_Credit:

This project is jointly funded by the Washington State Department of Ecology and the US Geological Survey, Coastal & Marine Geology Program. Original survey data courtesy US Army Corps of Engineers, Seattle District (Eric Nelson, pers. comm).

Water depth relative to NAVD88 was calculated by first determining the primary tidal station used for a particular survey. This information was obtained from original smooth sheets and/or descriptive reports where possible, or assumed where such information didn't exist. Relative offsets between MLLW and NAVD88 at each tidal station was determined based on geodetic information provided for NOS benchmarks, determined by independent geodetic surveys conducted by the Department of Ecology, or estimated where no other information was available. The NAVD88 values were thus calucalated by adding the relative differences between datums to the MLLW depth values. In some cases, a larger datum correction was applied to offset obvious bias in the original data set. An in-depth description of the methodolgy employed for these conversions, along with a discussion of specific corrections made, are available in Buijsman, et al., 2002.

DATA SET SPECIFIC INFORMATION:

For the data set: gh27anp
The primary tidal station used is: Pt. Chehalis, Westport (assumed)
The source used to determine the tidal station: No direct information was available regarding this survey. Modern USACE surveys use this tidal datum.
The vertical datum relative to NAVD88 is: -0.46 meters
The conversion applied to charted depths: -1.11 meters

Vertical adjustments were applied to all NAVD88 converted depths as discussed in Buijsman, et al. 2002